class_docstr: Converts featuresets and labeled featuresets to ARFF-formatted
  strings, appropriate for input into Weka.
  
  Features and classes can be specified manually in the constructor, or may
  be determined from data using ``from_train``.
docstr: Returns a string representation of ARFF output for the given data.
docstr_tok: ["Returns","a","string","representation","of","ARFF","output","for","the","given","data","."]
code: def format(self, tokens):
      """Returns a string representation of ARFF output for the given data."""
      return self.header_section() + self.data_section(tokens)
  
imports: import os
  import re
  import subprocess
  import tempfile
  import time
  import zipfile
  from sys import stdin
  from nltk.classify.api import ClassifierI
  from nltk.internals import config_java, java
  from nltk.probability import DictionaryProbDist
label_desc: Use image node_id 2 for calling the ARFF_Formatter obj's underlying member method code with example usage: obj.format(tokens) and returns: unknown